Nonlinear control of a variable frequency DC-DC converter

The paper deals with the nonlinear control of a variable frequency converter. The modelling of these converters is rather delicate, especially at low frequencies, where the average state model becomes inaccurate. Thus a global nonlinear discrete model is proposed. The linearization of this nonlinear model is only available for small variations around an operating point, which is shown and explained in this paper. For the high variations of the desired state output, it is necessary to use a nonlinear control law which takes into account the nonlinear dynamic of our discrete model. Our methodology is compared to the linear one